<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%--引用标签库--%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>JSTL标签</title>
</head>
<body>

<form action="jsp.jsp" method="get">
    <label>
        <input type="text" name="username" ${param.username}/>
    </label>
    <input type="submit" name="login"/>
</form>

<c:if test="${param.username == 'admin'}" var="isAdmin">
    <c:out value="欢迎你"/>
</c:if>

<c:out value="${isAdmin}"/>

</body>
</html>
